Automotive Air Conditioning Information Forum (Archives)

94RX-7 on Thu December 15, 2011 10:39 AM

Year: 1977
Make: Mazda
Model: REPU
Engine Size: 1.3L
Refrigerant Type: R-134a

I'm putting together a system for my 1977 REPU and I'm trying to decide whether or not to take "heroic measures" to put in a huge condenser, or if I can put a smaller condenser in the stock location. The options are:

Install a parallel flow unit around 11"x20" in the "factory" location and put two electric puller fans on the backside of it.

Install a unit as large as 20"x24", and completely reconfigure the radiator and oil cooler mounting, moving both toward the engine by an inch or so. This would also require that I ditch the stock belt driven fan and go to electric fans on the backside of the radiator. I would likely have to upgrade the alternator and do some re-wiring to handle the monster fan(s). This option would make plumbing the refrigerant lines slightly easier, but overall this option will be a lot more work.

I'm inclined to believe that since this is a small truck with fairly low heat loads, that the smaller option, with fans, will be sufficient, but I haven't been able to find any good info on how to size a condenser.

I'll be using the Mazda dealer installed under-dash evaporator unit which is a copper tube and fin design w/ expansion valve.